Apparatus for sanitizing a domestic clothes washer

ABSTRACT

A method and apparatus for sanitizing domestic clothes washer wherein a predetermined concentration of liquid sanitizing solution is first distributed throughout the washer and the washer&#39;&#39;s water recirculation system, then removed from the washer but retained in the water recirculation system.

[151; 3,702,069 1451 Nov. 7, 1972 United States Patent Sharpe [s4]APPARATUS FOR SANITIZING A Bochan 68/207 DOMESTIC CLOTHES WASHER Smithet al.................8/159 X 72] Inventor: verlos G. Sharpe, NorthfieldOhio 3,370,597 2/1968 R 3,376,720 4/1968 Hartshorn et al. .....68/l7 R X[73] Assigneez General Motors Corporation,

Detrolt Mlch' Primary ExaminerWilliam 1. Price July 1, 1971Attorney-Williams S. Pettigrew et a1.

[22] Filed:

[57] ABSTRACT A method and apparatus for sanitizing domestic [211 Appl.No.: 158,681

clothes washer wherein a predetermined concentration of liquidsanitizing solution is first distributed throughout the washer and thewashers water recirculation system, then removed from the washer butretained in the water recirculation system.

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References Cited I UNITED STATES PATENTS 3 Claims, 5 Drawing Figures2,611,256 9/1952 Candor ..........68/12R' PAIENTEnm m: v 3.702.069 sum 2or 4 HOT WASH HOT WASH COLD RINSE WARM RINSE WARM WASH COLD WASH COLDRINSE COLD RINSE EXTRA HEAVY HEAVY NORMAL LIGHT START START STARTSTARTWASH TWO 5 P E E D V PUSH TO SET OR STOP PULL TO START ENZYME ORREGULAR 'R I SOAK CYCLE I I SPIN DRY I SOAK SOAK CYCLE I N VEN TOR.

I r/os 6156x1406 ATTOR N EY PATENTEDW 19 2 3.702.069

SHEEI 3 OF 4 TIMER CYCLE CHART ON ONE COMPLETE ROTATIONAL CYCLE OFSIXTY-FIVE IMPULSES 5 IO 2o 3o 4o 5o 6O SWEI'CH LINE TI R

I MO

PAUSES PHASE WASH SPIN RINSE SPIN SOAK IGISANITIZE WASH CYCLE SOAK CYCLEFILLED IN AREAS INDICATE CONTACTS CLOSED E=CONTACTS MAY BE OPEN ORCLOSED III=CONTACT CLOSED FROM 6 TO 20 SECONDS ONE IMPULSE 72 SECONDS IN VEN TOR.

yer/0s azpe APPARATUS FOR SANITIZING A DOMESTIC CLOTHES WASHER TheUnited States Department of Agriculture has suggested that domesticclothes. washers may be sanitized occasionally to help prevent thespread of illness among family members. It is also a good practice forperiodic general housekeeping or for freshening.

and deodorizing the washer. There are some bacteria thatare notkilled attemperatures below 140 F. and many loads of clothes are washed in watermuch cooler than that. As a precaution against spreading bacteria fromone wash load to another, the washer can be sanitized with liquidchlorine bleach. Additional information about sanitizing can be found inthe U.S. De-

partment of Agricultures Home and Garden bulletin No. 97, Sanitizationand Home Laundry. This invention is directed to an improved method andapparatus for sanitizing a recirculating-type domestic clothes washer.

Accordingly, it is an object of this invention to provide a method ofsanitizing a domestic clothes washer which retains sanitizing solutionin the water recirculationsystem but not in the clothes washer aftersanitizing.

It is also an object of this invention to provide a domestic clotheswasher having dual water systems for recirculation and drain with atimer controlled sanitizingcycle and means to seal one water system fromthe other in order to retain sanitizing solution in one of said systemsafter the sanitizing cycle.

Another object of this invention is the provision of a timed wash cyclefor a domestic clothes washer which includes a sanitizing cycle as aconcluding portion of the timed wash cycle.

It is also an object of this invention to provide a sanitizing cycle fora domestic clothes washer which incorporates the terminal rinse fill,agitate and spin portion of a wash cycle and utilizes a partial fillwith a liquid chlorine bleach as the sanitizing solution.

Further objects and advantages of the present invention will be apparentfrom the following description,

reference being had to the accompanying drawings, wherein a preferredembodiment of the present invention is clearly shown. V

IN THE DRAWINGS FIG. 1 is a fragmentary side elevational view of adomestic clothes washer suitable for use with this invention and withparts broken away to show elements thereof to be sanitized;

FIG. 2 is a front elevational view of a control panel adapted for usewith the method and apparatus of this invention;

FIG. 3 is a timer cycle chart illustrating preferred cycles to wash andsoak clothes and to sanitize the clothes 2 sive with the cylindricalside wall of the spin basket. An annular plastic subtop 30 is sealinglyclamped to the open top of the water container 26. The subtopcircumscribes the open top of the water container and extends over a rim33 forming the top opening of the spin basket 28 to define an accesscollar 36 between the top opening in the clothes washer cabinet and thetop opening 33 of the spin basket.

In some washers of this type, it is desirable to continuouslyrecirculate washing fluid through a filter during the. agitate portionsof a wash cycle. For this purpose the clothes washer 20 may be providedwith a recirculation supply conduit 34 which receives water pumped fromthe water container 26 and returns it through a removable lint filterdrawer shown generally at 35.

The water container 26 and, thus, the tub assembly 24 is mounted on asuspension system more fully taught in U.S. Pat. No. 3,493,118 grantedFeb. 3, 1970. The tub assembly includes an agitator 44 which with thespin basket 28 is connected in movement effecting relationship to adrive mechanism or movement effecting means shown generally at 50. Thedrive mechanism may be of a roller-drive type taught more fully in U.S.Pat. No. 3,087,321 granted Apr. 30, I963. In general, mechanism may beoperated through a reversible motor 52 inone manner to verticallyreciprocate or oscillate the agitator 44 for washing clothes in the tubassembly. When mechanism 50 is operated in another manner, the spinbasket 28 is rotated with respect to the water container 26 forcentrifuging washing fluid from the clothes in the spin basket. I

A peripheral fill system is carried and supported on the annular plasticsubtop 30. The under side of the subtop includes a pair of integral ribs54, 56 which define a channel to receive a flexible fill tube 60arranged around the top opening 33 of the spin basket and adapted todirect a series of fan-shaped sprays downwardly into the spin basket.

Most of the spray enters the spin basket where it serves to wet down dryclothes placed in the clothes washer at the beginning of a clotheswashing cycle. This is insured by the depending rib 56 which diverts theoutboard portion of the spray downward. Rib 56 approaches rim 33 andalso serves thereby as a guard to prevent clothes from being spun intothe space 64 between the tubs. Later in the wash cycle after the theclothes have become plastered on the side of the spin basket duringcentrifuging, the spray serves to release the clothes from the side wallby breaking down the adhesion between the clothes and the spin basket.During the latter part of a SANITIZE" cycle, the spray serves to flushthe residue of sanitizing solution from the agitator 44 and the spinbasket 28, i.e., those parts of the washer which would expose fabric toinsufficiently diluted bleach if a wash cycle immediately followed asanitize cycle.

Clean wash water is supplied to the tub assembly 24 by means of theperipheral fill tube 60 which is connected to a domestic water supply.For additional details regarding the peripheral fill system for clotheswasher 20, reference may be had to the copending commonly assignedapplication Ser. No. 55,813, filed July 17, I970.

Water supplied to the tub assembly is recirculated during a clotheswashingoperation. The recirculation system includes the sump 66 joinedto and in communication with the'bottom 68 of the water container 26. Arecirculation pump 70 .is supplied from the sump by means of a conduit72 and returns water to the wash tub assembly 24 by means of the conduit34; Conduit 34 terminates at 74 on the subtop which leads to theremovable lint filter drawer through which the recirculating water flowson its way to the tub assembly.

Water isdrained from the tub assembly through the sump 66.-For thispurpose, a drain pump 76 is connected to the sump by means of aconduit78 and to a remote drain by means of a conduit 80. The upper drain pump76 and the lower recirculation pump are joined into a stacked pumpassembly 82 shown more particularly in FIG. 5.

The dual pump assembly 82 is comprised of the recirculating pump 70 andthe drain pump 76 stacked on top thereof. An upper pump housing 84 isclosed at the top by a 'pump cover 86-and upper pump housing gasket 87to form the pumping cavity 88 for the drain pump. It is closed at thebottomthereof by a lower pump housing 90 and lower pump housing gasket91 to form a recirculation pump cavity 92. A partition 94 integral withthe upper pump housing generally separates the cavity of the two pumps.A shaft 98 is directly driven fromthe reversible motor 52 by means of abelt and pulley arrangement 100 (FIG. 1). A lower pump impeller 102 isfastened .by a retaining ring 104 to a pump impeller stud 106. The studis threadedly engaged on the lower end of the drive shaft 98. Above thelower impeller 102 is the upper. pump impeller 110. The upper pumpimpeller is formed on a hub portion 112 the upper portion of whichoverfits. the drive shaft 98.,Between the pump cover 86 and the impellerhub 112 is a pump seal 114. The seal fits snugly into a socketof thepump cover and includes on its lower end an annular" sealing rib 116adapted to bear sealingly against anannular seal seat 118 which, inturn, is positioned in sealing engagement with the pumping cavity on aseal gasket 120.

In accordance with one aspect of this invention, it is important thatthe recirculation pump cavity 92 be sealed against fluid interchangewith the drain pump cavity 88.F or this purpose a sealing arrangement122 is provided between the central partition 94 and the rotatingimpellers. The sealing arrangement is comprised of a cup-like sealretainer 126 cradling in the center thereof an impeller seal 128 andoutboard thereof, an O-ringseal 130 between the retainer and a raisedannular rib 132 on the partition 94. Relative rotation occurs betweenthe seal 128 and the retainer 126 without permitting the interchange offluids from one pump cavity to the other. In this regard separation ofthe fluids in the drain and recirculation systems is enhanced in thesump also. The recirculation conduit 72 communicates directly with astandpipe 129 inside the sump 66 which extends upwardly to a pointslightly above the open top of the sump and the bottom 68 of the watercontainer. The entrance of stagnant drain pump water into therecirculating system is thus minimized- The construction of the agitator44 is adapted for use with the SANITIZE cycle of this invention. Forthis purpose, the agitator includes a hollow, central column andagitating cones 142. Openings 144 in the horns-- basket 28. The agitatorincludes a removable cap 148 which, when inverted, provides a measuringchamber having a capacity of one and one-half cups. A removable bleachcup 150 inserts within the column 140 and is retained therein by theagitator cap 148. This forms a bleach dispensing arrangement of the typetaught in U.S. Pat. No. 3,306,084 granted Feb. 28, 1967.

The WASH cycle and the SOAK" cycle will not be described in detail butmay beunderstood with reference to the wiring diagram (FIG. 4) and thetimer cycle chart (FIG. 3). The SANITIZE cycle embraces the terminalportion of the fWASI-I cycle.

The SANITIZE cycle will now be described with reference to FIGS. 2, 3and 4. The user may sanitize the washer 20 as follows. Usingthe-inverted cap 148 as a measure, 1 k cups of liquid chlorine bleach ordisinfector. The dials 160, 162, 164 and 166 are set as shown in FIG. 2.FIG. 4 represents control circuitry at the start of a SANITIZE cyclewith the dials in the shown positions.

More particularly, dial programs a water temperature switch 170 to thepositions shown in FIG. 4 to control a hot water valve solenoid 172 anda cold water valve solenoid 174 to provide a warm water fill.

The speed selector dial 162 controls a speed selector switch 176 toposition the switch to condition the motor 52 for slow speed. Thisproduces 240 strokes per minute. at the agitator 44 during rinse andabout 425 r.p.m.- spin of the spin basket 28 during spin.-

I The load selector dial 164 conditions a water level switch 180 toprovide a MINI fill of water. The switch 180 may be of a pressuresensitive type which is programmed by the turn of the dial'164 toprovide a variety of water levels in tub 26 from 10 k gallons at MINI?fill to 2.1 gallons at MAXI fill. The pressure fill control systemconsists of the pressure switch 180, drain sump 66 with built-on airpressure chamber 67. A

plastic tube 69 connects the pressure chamber to the pressure switch.The operation of the fill control system contact 181 is closed andremains so as the water comes into the tub and fills the drain sump 66.As the water level rises the air in the air chamber 67 becomescompressed, and the compressed air acts against the diaphragm in thepressure switch. As the pressure increases it overcomes the springtension being applied against the diaphragm. The spring tension varieswith the setting of the water level desired. For a MAXI load the tensionis greater against the diaphragm than when a MINI" load selection ismade. With this control any water level may be selected according to thesize of the load.

When the compressed air overcomes the spring tension the switchactivates. This causes the switch to transfer from contact 181 tocontact 190. This breaks the flow of current to the water valve andmakes the circuit to the timer motor and drive motor for agitateoperation.

For the purpose of the SANITIZE cycle the MINI fill is selected. Thisselection in conjunction with the l 92 cups of liquid chlorine bleachprovides the preferred concentration of sanitizing solution. In washershaving the nominal 18 pound clothes load capacity of clothes washer 20but without variable fill, a similar concentration may be provided with3 cups of liquid chlorine bleach in a full water fill of 19 gallons.

The clothes washer timer is set to provide the timer switch positions inFIG. 4 for timer switch contacts 1, 3, 4, 5,7, 8, 9, l0, 11, 12,13,14,15 and 16 when dial 166 (FIG. 2) is set to the SANITIZE setting Thissetting coincides with either the 18th or 19th impulse on the timercycle chart (FIG. 3). The rotation of dial 166 advances the timerthrough the first eighteen impulses on the timer cycle chart. Aftervthisdial setting rotation, the dial 166 is pushed inwardly to close apush-pull switch 184. Lid switch 186 is closed whenever the top clothesaccess lid (not shown) is closed.

A MINI fill of warm water is provided as follows. The hot water valvesolenoid 172 is energized from L-l through lid switch 186, a tubunbalance relay switch 188, push-pull switch 184, load selector switch180 (on its tub-empty contact 181), timer switch contact 14, watertemperature switch 170 to the hot water valve solenoid 172. The coldwater valve solenoid 174 is energized in the same'fashion to timerswitch contact 14 from which it is energized by means of timer switchcontact 16. Ten and one-half gallons of warm water are thus provided tothe outer water container 26. Fill is completed in response to filldepth pressure when the load selector switch 180 moves to contact 190and timer motor 192 is energized through timer switch contact 3. Thetimer cycle is now advanced out of the 18th timer impulse (where thedial setting was in 18) into the 19th timer impulse of (where the dialsetting was in 19) the timer motor starts when the water fill iscompleted. Timer switch contact 1 is closed in the 20th impulse alongwith additional timer switch contacts 7, 9 and 12 to energize the mainmotor 52 in a direction to provide agitation of the agitator 44 at theslow speed setting predetermined by the speed selector dial 162 andswitch 176. This dispenses the bleach gradually from cup 150 andagitator 44 to form a sanitizing solution with the warm water in the tub26. Agitation is provided through the 21st timer impulse to distributesanitizing solution throughout the clothes washing area. Thereafter, atime pause occurs to reverse the motor and reenergize it to rotate spinbasket 28 and pump the sanitizing solution from the wash area within thespin basket.

During the 23rd timer impulse, timer switch contact 14 is closed toinitiate a brief (6 to 20 seconds) spray of fresh clean water (about 1gallon) from the peripheral spray tube 60. The plurality of fan-shapedsprays flush the outer surface of the agitator 44 and the inner surfaceof the spin basket 28 to remove all traces of the liquid bleach"sanitizing solution. It is important that some means be provided toflush the sanitizing solution from the clothes engaging components wherea load of colored clothes is to be put through a WASH cycle immediatelyafter a SANITIZE cycle.

Referring now to FIG. 5, the operation of the pump assembly 82 will bedescribed in the context of a SANITIZE cycle. While the agitator isdistributing sanitizing solution to sanitize the clothes washing area,the recirculation pump 70 operates to withdraw sanitizing solution fromwater container 26 through sump standpipe 129 and conduit 72. Thissanitizing solution is then returned to the tub assembly by means ofconduit 34 and the entire recirculation system is thus sanitized. Whenmotor 52 and thus pumps 70, 76 are reversed to purge the tub assembly ofthe sanitizing solution, a small amount of the sanitizing solutionremaining in pump 70 and-its associated conduits 34, 72 and 129 isreturned to the bottom 68 of the water container whereit enters sump 66and is pumped from the clothes washer to drain by drain pump 76 alongwith the diluted sanitizing solution and its associated conduits 78, 80.The drain pump 76 operates to remove sanitizing solution to drain solong as the SANITIZE cycle is in spin. Note that the clean flushingwater which is sprayed during the 23rd timer impulse is removed to drainduring the spin portion of the SANITIZE cycle.

Some sanitizing solution is not purged from the recirculation system ofthe clothes washer during spin and remains in the recirculation pump 70and its associated conduits 72v and 34 to continue the sanitationthereof after the SANITIZE cycle. In this regard, it is important thatthe residue of water in the drain pump system not interchange with thesanitizing solution in the recirculation pump 70 either prior to thetermination of the SANlTlZE cycle or at the start of the next succeedingWASH or SOAK cycle. The sealing arrangement 122 together with standpipe129 provide for segregating the two pump cavities and the systems forrecirculation and drain. Thus when the clothes washer is not in use, thestagnant liquid in the recirculation pump 70 is sanitizing solutionwhich continues to disinfect by fighting the growth of bacteria. Thestrength of the sanitizing solution, of course, decreases with time(little effect after. 48 hours) but it remains strong enough to resistthe growth of bacteria for an extended period (up to 24 hours) after theSANITIZE cycle. This is important for the reason that at the start of asubsequent WASH cycle, the recirculation pump first starts by pumpingthe residual liquids in the recirculation system back into the wash tubassembly and onto the clothes load. On the other hand, the firstoperation of the drain pump 76 is to pump away from the tub assembly todrain.

It should now be seen that an improved method and apparatus have beenprovided for sanitizing a domestic clothes washer whereby sanitizingsolution is added at a predetermined point in a timer programmed washingcycle which avoids rinsing the sanitizing solution from the clotheswasher. Moreover, the improved sanitizing method and apparatus providefor retaining a residue of sanitizing solution in the recirculationwater system by sealing it from the drain water system.

While the embodiment of the present invention as herein disclosedconstitutes a preferred form, it is to be understood that other formsmight be adopted.

I claim:

1. A clothes washing machine comprising, a rotatably mounted perforatedclothes receptacle, means for effecting movement of clothes and liquidin said clothes receptacle; an imperforate liquid receptaclesubstantially surrounding said clothes receptacle so as to retainliquidwithin said clothes receptacle, said liquid receptacle having a drainand recirculation sump formed in the bottom thereof; a reversible rotarypump structure including first and second pumps secured along a commonpartition to operate together, each of said pumps having first andsecond openings, each of said pumps adapted to draw in liquid throughits first opening and discharge it through its second opening whenrotated in one direction, each of said pumps adapted to draw in liquidthrough its secondopening and discharge it through its first openingwhen rotated in the opposite direction, a common reversible drive motorfor said pumps, said clothes receptacle and said movement-effectingmeans, operation of said motor in a first direction rotating .said pumpsin said one direction and operating said movement-effecting means,operation of said motor in a second opposite direction rotating saidpumps in said opposite direction and rotating saidclothes receptacle ata centrifuging speed, first conduit means connected atone end to saidfirst opening of said first pump and adaptedv to discharge fromits'other end into a drain, second con-v means for dispensing apredetermined quantity of disinfectant into the predetermined load ofwater supplied to form a sanitizing solution, and timer means forconduit means connected at one end to said second opening of said firstpump and at its other end to said sump, third conduit means: connectingsaid sump with said first opening of said second pump and'includingmeans separating. the connection thereof with said sump from theconnection of said second conduit means with said sump, fourth conduitmeans having one end connected to said second opening of said secondpump and having its other end positioned to discharge into the top ofsaid clothes receptacle; sealing means in said common partition toprevent the interchange of liquids between said pumps, means forsupplying said liquid receptacle trolling said reversible drive motorand said filling means in a sanitize cycle including sequential periodsof time water fill, rinse agitate, rinse spin, rinse water flush andspin dry, said timer means controlling said water supply means andadapted therewith to supply a small load of warm water during said rinsewater fill periodand thereafter controlling'said water supply means tosupply a flushing load of water during said rinse water flush period,said timer means controlling said drive motor for operation in onedirection while said sanitizing solution is being formed by saiddispensing means to recirculate said sanitizing solution onto saidclothes receptacle and said movement-effecting means during said rinseagitate period, and said timer means controlling said drive motor foroperation in the opposite direction during said periods of rinse spin,rinse water flush and spin dry to drain said sanitizing solution andsaid flushing load of water, said sealing 4 means enabling said secondpump to retain a portion of said sanitizing solution in said second pumpafter the completion of said sanitize cycle. v

2. The clothes washing machine of claim 1 wherein saidmovement-effecting means includes an agitator in said clothes receptacleand said agitator encloses said dispensing means.

3. The clothes washing machine of claim 1 wherein tastings, nas i ctantis ch orme each and said predetermined quantity thereof is 1% cups, andsaid flushing load is 1 gallon.

1. A clothes washing machine comprising, a rotatably mounted perforatedclothes receptacle, means for effecting movement of clothes and liquidin said clothes receptacle; an imperforate liquid receptaclesubstantially surrounding said clothes receptacle so as to retain liquidwithin said clothes receptacle, said liquid receptacle having a drainand recirculation sump formed in the bottom thereof; a reversible rotarypump structure including first and second pumps secured along a commonpartition to operate together, each of said pumps having first andsecond openings, each of said pumps adapted to draw in liquid throughits first opening and discharge it through its second opening whenrotated in one direction, each of said pumps adapted to draw in liquidthrough its second opening and discharge it through its first openingwhen rotated in the opposite direction, a common reversible drive motorfor said pumps, said clothes receptacle and said movement-effectingmeans, operation of said motor in a first direction rotating said pumpsin said one direction and operating said movement-effecting means,operation of said motor in a second opposite direction rotating saidpumps in said opposite direction and rotating said clothes receptacle ata centrifuging speed, first conduit means connected at one end to saidfirst opening of said first pump and adapted to discharge from its otherend into a drain, second conduit means connected at one end to saidsecond opening of said first pump and at its other end to said sump,third conduit means connecting said sump with said first opening of saidsecond pump and including means separating the connection thereof withsaid sump from the connection of said second conduit means with saidsump, fourth conduit means having one end connected to said secondopening of said second pump and having its other end positioned todischarge into the top of said clothes receptacle; sealing means in saidcommon partition to prevent the interchange of liquids between saidpumps, means for supplying said liquid receptacle with predeterminedfull or small loads of warm water, means for dispensing a predeterminedquantity of disinfectant into the predetermined load of water suppliedto form a sanitizing solution, and timer means for controlling saidreversible drive motor and said filling means in a sanitize cycleincluding sequential periods of rinse water fill, rinse agitate, rinsespin, rinse water flush and spin dry, said timer means controlling saidwater supply means and adapted therewith to supply a small load of warmwater during said rinse water fill period and thereafter controllingsaid water supply means to supply a flushing load of water during saidrinse water flush period, said timer means controlling said drive motorfor operation in one direction while said sanitizing solution is beingformed by said dispensing means to recirculate said sanitizing solutiononto said clothes recepTacle and said movement-effecting means duringsaid rinse agitate period, and said timer means controlling said drivemotor for operation in the opposite direction during said periods ofrinse spin, rinse water flush and spin dry to drain said sanitizingsolution and said flushing load of water, said sealing means enablingsaid second pump to retain a portion of said sanitizing solution in saidsecond pump after the completion of said sanitize cycle.
 2. The clotheswashing machine of claim 1 wherein said movement-effecting meansincludes an agitator in said clothes receptacle and said agitatorencloses said dispensing means.
 3. The clothes washing machine of claim1 wherein said full load is 21 gallons, said small load is 10 1/2gallons, said disinfectant is liquid chlorine bleach and saidpredetermined quantity thereof is 1 1/2 cups, and said flushing load is1 gallon.